Speed Passion V3 motor plugs unsoldering themselves

[Big G]

My 6.5 was the biggest culprit of this. During the race it would just unsolder terminal A leaving the car stranded with steering, but no gas. The plugs are covered in solder so the connection is good. no dry joints!

re-soldered back on and sometimes it would do it again next race or sometimes it would go for weeks no problem. This happened indoors and outdoors where gearing was varied and the motor was never too hot to touch.

I don't remember this ever happening in my B44, just in the Cat and I think once or twice in the B4.

On disassembly of my 6.5 I noticed the A terminal was wobbly on the PCB and had burn marks around it. I figured this must be generating extra heat melting my solder. So the 6.5 was condemned. In went the 7.5. A few meetings later same thing happening. The A terminal again had a slight wobble to it. nothing at bad as the 6.5 though. then the 7.5 stopped working all together and won't run without wiggling the A plug. I don't swap the motors twice a week only every now and then so I wouldn't say there was excessive force on the terminals

In went my last V3 motor the 5.5. Again this happens! It's really starting to annoy me now having £150 of dead motors which I can only related to this problem not to mention the races I've had to retire from

Something that did cross my mind is I run the larger power cap of 4 capacitors on this LPF of mine. Could this possibly be related? I didn't buy it, it came with a 2nd hand SP LPF speedo I bought on ebay...

Until Taly this weekend it's always been terminal A, but on Sunday it was plug B

Any ideas?
I'm going to reinstall the standard power cap that comes with the speedo and see if that makes any difference.

[GRIFF55]

check all your plugs going to the motor are a tight fit and dont wiggle on the motor connections and also the ones to the lipo are a secure fit.
let us know your findings mate

[Big G]

I've used brand new plugs on the motor as well as ovaling a old plug to make the fit tight to try and stop the wobble.

can't be the motor as it's doing it on all 3 of mine. I can only think it's the speedo or the power cap.

I've used new wire aswell. and my lipos are 3 weeks old.

[DCM]

Agree with Andy, check the 'fit' of the plugs into the motor, if they are a little loose, change them, the little 'play' will cause it to overheat and melt the solder, also, look at your wiring layout, so it isn't pulling on the connector!

[RogerM]

G ... interesting this. I have been running my Speed Passion stuff for around a year now with no issues at all. I only have 2 motors that I use (8.5 and 6.5) and they sometimes get swapped between the cars regularly but sometimes are left in for months at a time too. My cars are always commented on as "being a bit hot" as I have found the Speed Passion stuff likes to be geared a touch higher than most so if it was heat then I would have had a failure by now I am sure!

Only thing I could think of that is different between our two situations is that you run a cat with it's 'alternative' motor mounting method and that could be putting different vibration signitures into the connectors.

Do you have the wires tied down or free to wiggle about? I always keep my wires tethered so there is no relative movement at the connector, originally I was concerned about a connector falling out but they have always been rock solid ... actually sometimes VERY stiff to remove.

Hope you find the root cause.

[markwilliamson2001]

Have to say Gareth, I have no problems with this at all. I did notice that your wires were very very short in your Cat last time out, so any flexing will be exaggerated. In my b44, I have never had a problem like this at all, or in my B4, so I would invest in some new plugs, and get someone else to solder them for ya!

Let me know how it goes.

[Big G]

My wires are free to move if they desire (not a lot though). Granted my wires in the cat are reasonably short, they are longer than my original install where they ran down the side of the chassis. they now run the width of the speedo then round to the motor. I think slightly longer than the original install. I wouldn't of thought pulling on them should do this. they would have to get hot enough for the solder to let go wouldn't they? I think durango installs have shorter wires than mine... come to think of it I wouldn't have said they were much shorter than in the B44. When I 1st got the cat I just lifted the speedo out of the B44 and straight in without touching the wires.

Last night I installed the original power cap and ran the 10.5 all night without any problems at all. fantastic motor for ludlow!

I will continue to monitor the issue now running the 10.5. This was geared on 23/81 and temp gunned at 136 after a race with 2-4 warm up laps.

If it's the speedo at fault I'll treat myself to a new Pro version

[DaveG28]

Originally Posted by DCM

Agree with Andy, check the 'fit' of the plugs into the motor, if they are a little loose, change them, the little 'play' will cause it to overheat and melt the solder, also, look at your wiring layout, so it isn't pulling on the connector!

Hmm, I have a problem on this. My C connector on the motor side is not wide enough, so I now have to crimp the plug on the esc wire, which I'm worried will overheat???

So, can you get replacements for the part attached to the motor itself?

[Big G]

Dave, do you mean the male part of the plug?

[DaveG28]

Originally Posted by Big G

Dave, do you mean the male part of the plug?

Yep, it's tightish now I crimped the female, fingers crossed it works! Don't want to have to get a whole new motor!?